Quantum dots (QDs) are positioned to revolutionize point-of-care testing (POCT), with their exceptional brightness, photostability, and multiplexing capabilities being leveraged to enable real-time, in-situ detection with practical utility. In this review, recent advances in QD-based sensing are systematically summarized, with emphasis placed on how precise control over synthesis and surface functionalization across key material families (e.g., chalcogenide QDs) has facilitated the development of a versatile analytical toolkit. Diverse transduction mechanisms, including fluorescence, colorimetric, electrochemiluminescence, photoelectrochemical, and chemiresistive sensing, are explored, and their deployment across biomedical diagnostics, environmental surveillance, and food safety is highlighted. Moving beyond a mere summary of progress, this review focuses on addressing the critical challenges that currently hinder the practical translation of QD-based sensing technologies. Key issues include the biotoxicity of heavy-metal-containing QDs, their limitation in complex sample matrices, performance gaps in emerging “green” QDs, and hurdles in device integration and data analysis. A coordinated strategy is therefore proposed, centered on greenification, intellectualization, and integration. It is envisioned that through advances in biocompatible materials, integration with portable platforms such as microfluidics and smartphones, and the incorporation of machine learning for intelligent signal processing, QDs will be propelled from laboratory tools into foundational, democratized technologies for next-generation POCT. The strategic framework presented here provides a clear roadmap to guide future research and translation efforts in QD-POCT.

Spermine assumes a pivotal role in assessing food safety due to its potential to induce a spectrum of diseases upon excessive consumption. However, contemporary spermine detection methodologies, exemplified by high-performance liquid chromatography (HPLC), demand costly instrumentation and the expertise of skilled technicians. To address this challenge, the study introduces a portable fluorescence sensing platform. Ratiometric fluorescent probes were realized through the utilization of CdS quantum dots deeply doped with Ag⁺ (CdS:Ag QDs) and nitrogen-doped carbon quantum dots (N-CQDs). Hydrogen bonds formed between CdS:Ag QDs and spermine result in the formation of the assembly and the decreasing of the fluorescence intensity. In an effort to broaden the applicative scope and streamline deployment processes, fluorescent sensing hydrogels were meticulously engineered, capitalizing on the swelling properties inherent in polyvinyl alcohol (PVA) hydrogels. The systematic delineation of the correlation between 1 − R/B and spermine concentration facilitates the quantitative determination of spermine concentration. The incorporation of this composite construct serves to alleviate environmental influences on the probes, thereby augmenting their precision. The portable fluorescent sensing platform proves pivotal in expeditiously measuring spermine concentration within the fluorescent sensing hydrogel, enabling a quantitative assessment of pork freshness. The utilization of this platform for food freshness evaluation imparts the benefits of convenience, cost-effectiveness, and intuitive operation.